【作者】 张志勇；

【导师】 洪晓月； 刘贤金；

【作者基本信息】 南京农业大学 ， 农业昆虫与害虫防治， 2008， 博士

【摘要】 农药的发明和使用大大提高了作物的产量,但随着农药的大量特别是不合理的使用,食品中的农药残留对人类健康造成的负面影响也日益显露出来。近几年来,我国蔬菜中农药残留引起的中毒事故频繁发生,农药残留对消费者的身体健康构成了严重的威胁,引起人们的高度重视。开展叶菜类蔬菜农药残留防控体系研究无疑是控制农药残留、保证食品安全的基础,因此具有重大的现实意义。本课题从药剂混用对其残留规律的影响、不同季节蔬菜农药残留规律、蔬菜低残留农药筛选及其残留规律、低残留农药环境安全性评价及产后蔬菜表面残留农药去除方法进行了研究,取得了如下进展。1.药剂混用、秋季小青菜和春季甘蓝上农药残留规律研究了农药混用、秋季小青菜和春季甘蓝上农药残留规律。在相同用药条件下,有机磷类杀虫剂混用、拟除虫菊酯类杀虫剂混用、有机磷类和拟除虫菊酯类杀虫剂及杀菌剂百菌清混用后对各药剂的残留没有明显影响。在秋季小青菜上,按推荐使用中间剂量使用1次时,毒死蜱、乐果、三氟氯氰菊酯、氯氰菊酯、氰戊菊酯、溴氰菊酯、百菌清7种农药的半衰期分别为4.71天,5.28天,2.85天,3.50天,5.40天,4.34天和3.96天,根据农业行业标准推荐的安全间隔期,除毒死蜱外,其他农药的最终残留量均在国家规定的最大残留限量(MRLs)范围之内;当毒死蜱、氯氰菊酯、百菌清在推荐最大剂量使用4次(间隔5天用药1次)时,3种农药的半衰期分别为4.92天,3.78天和5.93天,按照农业行业标准所推荐的安全间隔期,毒死蜱和百菌清的最终残留量超过其最MRL,但氯氰菊酯的最终残留量仍然在其MRL范围之内。在春季甘蓝上,按推荐使用中间剂量使用1次时,以上7种农药的半衰期分别为2.03天,1.57天,1.64天,2.34天,2.16天,1.51天和1.80天,根据农业行业标准推荐的安全间隔期,所有农药的最终残留量均在国家规定的MRL范围之内;当毒死蜱、氯氰菊酯、百菌清在推荐最大剂量使用4次(间隔5天用药1次)时,3种农药的半衰期分别为2.90天,2.62天和4.06天,按照农业行业标准所推荐的安全间隔期,只有百菌清的最终残留量超过其MRL,但毒死蜱和氯氰菊酯的最终残留量仍然在其MRL范围之内。春秋两季蔬菜上农药残留规律表明,影响农药残留量的最主要的因素是农药的理化性质、用药量、用药次数以及气候因素。2.叶菜类蔬菜高效低残留农药筛选及其残留规律研究研究了氯菊酯、胺菊酯、联苯菊酯3种拟除虫菊酯与敌敌畏、辛硫磷2种易光解的有机磷类杀虫剂及拟除虫菊酯与有机磷类杀虫剂的二元混剂对蔬菜常见害虫菜青虫和小菜蛾的室内生物活性、田间药效和残留规律。室内生物活性和田间药效试验结果表明,供试的5种单剂及6种二元混剂对菜青虫和小菜蛾均有较高的活性,6种二元混剂对菜青虫和小菜蛾的田间防效均为90%以上,而且对作物安全。田间残留动态研究表明,药剂混用后,其原始沉积量和半衰期较单剂均有所减少。若在叶菜类蔬菜生产中选用以上几种杀虫剂组合,则既能有效控制虫害的发生,又能降低蔬菜中农药残留的水平,可从根本上提高蔬菜的质量安全。3.低残留药物对非靶标生物的急性毒性分别研究了氯菊酯、胺菊酯、联苯菊酯、敌敌畏、辛硫磷和50:50拟除虫菊酯与有机磷杀虫剂的二元混剂对非靶标生物斑马鱼和家蚕的急性毒性。所有拟除虫菊酯类杀虫剂对斑马鱼均为剧毒,辛硫磷为高毒(48、72和96 h处理)或中毒(24 h处理),而敌敌畏为低毒;二元混剂中氯菊酯或联苯菊酯与敌敌畏或辛硫磷混剂对斑马鱼的毒性仍然为剧毒,但胺菊酯与敌敌畏或辛硫磷混剂对斑马鱼的毒性为高毒;所有混剂对斑马鱼的联合作用除联苯菊酯与敌敌畏在72 h表现为拮抗作用外,其他混剂均表现为相加作用。所有试验单剂除联苯菊酯对家蚕为剧毒外,其他4种农药单剂对家蚕的急性毒性均为高毒;二元混剂中,除了胺菊酯与敌敌畏混剂对家蚕为中毒外,其他混剂均为高毒;二元混剂对家蚕的联合作用除了胺菊酯与敌敌畏的混剂表现为拮抗作用外,其他混剂均为相加作用。因此,在靠近水稻田、池塘和桑园的菜地应尽量避免使用这些药剂,以免对非靶标生物产生不利影响。4.蔬菜叶片表面农药残留日常去除技术在实验室模拟了不同浓度的盐溶液、醋酸溶液,自来水,冷藏和烹饪对甘蓝叶片表面有机磷农药(毒死蜱、乐果)、有机氯农药(p,p-DDT、γ-666)、拟除虫菊酯农药(溴氰菊酯、氯氰菊酯)、杀菌剂(百菌清)7种农药的去除效果。结果表明:在相同浓度和处理时间下,醋酸溶液对甘蓝叶片表面7种农药的去除效果要好于盐溶液,自来水对7种农药的去除效果在3种处理溶液中最差。冷藏12-48 h对甘蓝叶片表面残留农药去除没有显著影响,烹饪对以上7种农药的去除率均在65%以上,而且对有机磷类和拟除虫菊酯类杀虫剂及杀菌剂百菌清的去除效果要好于有机氯类杀虫剂。因此,建议蔬菜最好充分洗涤、烹饪后食用,尽量不要生食。更多还原

【Abstract】 The invention and application of pesticides greatly increase the output of crop production. With the excessive and fallacious use of pesticides, their residues in food, however, cause a lot of ill-influence on human’s health. In recent years, poisoning accidents caused by the pesticide residues in vegetables were reported frequently in the country, which seriously threaten the consumers’ health. People have since been aware of pesticide residues in vegetables production. Undoubtedly it is of great importance and the foundation of controlling pesticide residues and assuring the food safety that a study on inspection and management system for pesticide residues in leafy vegetables conducted. Therefore, our research conducted include residual dynamics of mixture of pesticide, pesticides in different season vegetables, low residual levels insecticides screening and its environmental safety assessment, and removal method for pesticides residues in cabbage leaf surfaces. The main results are listed as follows.1. Residual dynamics in mixture of pesticide, autumn Chinese cabbage and spring cabbagePesticides residual dynamics of chlorpyrifos, dimethoate, cyhalothrin, cypermethrin, fenvalerate, deltamethrin and chlorothalonil in the autumn Chinese cabbage (Brassica chinensis L.), spring cabbage (Brassica oleracea L. Var. capitata) and its mixture were studied. The results indicated that mixed use of pesticides did not have significant effects on pesticide residue levels, initial concentrations and half-lives. When the autumn Chinese cabbages were treated once at recommended middle rates, the half-lives of the seven pesticides in the vegetable were 4.71, 5.28, 2.85, 3.50, 5.40, 4.34 and 3.96 days respectively. Thus, based on the recommended pre-harvest intervals, the residual levels of all pesticides were within the MRLs except for chlorpyrifos. When the autumn Chinese cabbages were treated four times at maximal rates at 5 day intervals, the half-lives of chlorpyrifos, cypermethrin and chlorothalonil in the vegetable were 4.92, 3.78 and 5.93 days respectively, so that, based on the recommended pre-harvest intervals, the residual levels of chlorpyrifos and chlorothalonil exceeded the MRL, but the residual level of cypermethrin was within the MRL. In the spring cabbage, if the cabbages were treated one time at recommended middle dosage of pesticides, the half-lives of the seven pesticides in the vegetable were 2.03, 1.57, 1.64, 2.34, 2.16, 1.51 and 1.80 days, respectively. And all pesticides maximum residue limits were not exceeded according to the recommended pre-harvest interval. However, if the vegetables were treated four times at the maximal dosage with a five-day’s interval, the half-life of chlorpyrifos, cypermethrin and chlorothalonil in the vegetable were 2.90, 2.62 and 4.06 days, respectively, and the final residual amount of chlorothalonil exceeded its MRL on cabbage, but the final residual amounts of cypermethrin and chlorpyrifos were below its MRLs on the cabbage. Pesticides residues data in autumn Chinese cabbage and spring cabbage clearly showed that the pesticides residues were dependent on the frequency and rate of pesticide application and on the weather conditions immediately following spraying.2. Screening high efficacy and low residual insecticides on leafy vegetables and insecticide residual dynamics in fieldRoom bioassay, field efficacy and residual dynamics were carried out to evaluate pesticides (permethrin, tetramethrin, bifenthrin, dichlorvos, phoxim and 50:50 binary mixtures of pyrethroid and organophosphate) against two pests (Pieris rapae and Plutella xylostella). Room bioassay results showed the efficacy against Pieris rapae and Plutella xylostella of pyrethroids were higher than organophosphates. All tested insecticides efficacy against Pieris rapae were better than Plutella xylostella. The 50:50 binary mixtures of pyrethroid and organophosphate showed synergism or additive. Field effectiveness results showed that the field efficacy against Pieris rapae and Plutella xylostella of binary mixtures of pyrethroid and organophosphate aboved 90%. The insecticides are safe to crops at the dosages. The initial concentrations and half-lives were decreased when the insecticides were used in mixture. In pollution-free vegetable production, these insecticides mixtures can effectively control the pest in vegetables, decrease pesticide residues, and improve the quality and safety level of vegetables.3. Acute toxicity to non-target organism of low residual level insecticidesAcute toxicities to zebrafish and silkworm of two organophosphorus insecticides (dichlorvos and phoxim), four pyrethroid insecticides (permethrin, tetramethrin and bifenthrin) were determined. The data indicated that the acute toxicities to zebrafish of all tested pyrethroids were special high, phoxim were high (48, 72 and 96 h exposure) or middle (24 h exposure), but dichlorvos were low grade. The acute toxicities to zebrafish of 50:50 binary mixtures permethrin or bifenthrin with organophosphates were special high too; however, the mixtures of tetramethrin with organophosphates were high grade. The joint effects of pyrethroid and organophosphate were additive, except for the mixture of bifenthrin with dichlorvos, it showed antagonism (72 h exposure). Acute toxicities to silkworm of all tested insecticides were high, except for bifenthrin, it showed special high grade. Acute toxicities to silkworm of all tested 50:50 binary mixtures of pyrethroid and organophosphate were high, except for the mixture of tetramethrin and dichlorvos, it showed middle grade. The joint effects of all tested 50:50 binary mixtures were additive, except for the mixture of tetramethrin with dichlorvos, it showed antagonism (24 and 48 h exposure). Therefore, these insecticides should be prohibited in or near to paddy, pond and mulberry orchards, to avoid side effect on non-target organism.4. Removal techniques of pesticide residues in cabbage leaves surfaceRemoval efficacies of organophosphates (dimethoate and chlorpyrifos), orgnaochlorine (p,p-DDT andγ-666), pyrethroids (deltamethrin and cypermethrin) and fungicide chlorothalonil residues in cabbage leaves surface caused by different concentrations of salt solution, acetum, tap water, refrigeration and cooking were simulation studied in laboratory. In the same treatment concentration and time, effect of acetum on 7 pesticide residues in cabbages surfaces were high than salt solution. The tap water treatment was the worst. There are no significant effects on pesticide residues in cabbage that refrigeration 12-48 h. The removal efficacy caused by stir-frying was above 65%, and the effects on organophosphates, pyrethroids and fungicide chlorothalonil were greater than organochlorine. It is suggested that citizens should wash cabbage carefully and stir-frying before eat it. Raw eating current situation of pesticide application on cabbage is not encourages.更多还原